The Japanese Patent Published Application No. 2004-85524 by the present applicant discloses a golf game system including a game apparatus and golf-club-type input device (operation article), and the housing of the game apparatus houses an imaging unit which comprises an image sensor, infrared light emitting diodes and so forth. The infrared light emitting diodes intermittently emit infrared light to a predetermined area above the imaging unit while the image sensor intermittently captures images of the reflecting object of the golf-club-type input device which is moving in the predetermined area.
The motion of the golf-club-type input device can be detected by processing the stroboscopic images of the reflecting object.
However, the scope of costs as required differs from business to business, and thereby it is sometimes required to develop and manufacture a product at a lower cost.